When it comes to microservice architecture and data consistency, are you a purist or a pragmatist? The microservice purist takes the position 1) that every microservice needs its own database, 2) that distributed transactions are an anti-pattern, and 3) that data only needs to be eventually consistent. On the other hand a data consistency purist takes the position 1) that data consistency is paramount, 2) that isolation is mandatory, and 3) that data must be globally consistent. Neither is right or wrong and real applications require pragmatic trade-offs between these positions. The pragmatist looks at the context of any requirement to determine what trade-offs may need to be made. Should you trade-off data consistency for performance? Should you accept some temporal coupling to achieve better data consistency? This session will examine the purist positions and propose some pragmatic trade-offs to consider when designing a microservice based application.